First time I saw this guy, he was inside a hole in the rock and I assumed he was part of it. Then it moved up into the little cave it's in now.

In shape it kind of reminds me of a hoof. The front is relatively flat, half is lighter pink, half darker purple. The sides are kind of tan colored and it's got a whitish thing attaching it to the rock. During the day it's usually pulled back against the rock and closed. At night it sort of opens - the top tip moves forward and the tips move apart a little in the middle revealing what look like maybe dark filaments.

Because of where it's positioned, I could only get an ok picture of it in the open position. It's the thing smack in the middle of the picture. (The white spots are spinoid worms tubes that stuck to him.)


Any ideas what it could be? Its movement kind of reminds me of a bivalve, but I've never seen one with a shell that shape.

I really can't tell anything from the pic; others may chime in.

Is it hard or soft? If it's hard, that'll probably rule out tunicates or sponges.

It's outlined in red so you can see what I'm taking about better.



This pic is a little dark, but here's what it looks like closed.



And closed and outlined:


It's hard. I'm sure it's not a sponge or tunicate - it doesn't look anything like either to me and it moves too much.

e.t.a. - Wow those last pics look bad. Someday I'll get a better camera...

That could be a tunicate, or it could be bigfoot, equally blurry

Its not the cameras fault... bigfoot IS blurry

The way the it looks like a Y it could almost be a flat worm of some sort.
Pull it out and put it on a white plate to take a pic of it. That will help.

it's a bivalve.

+1 to a bivalve. I can't think of anything else sessile that would exhibit the characteristics you've mentioned.

As for a specific species... good luck with that.

+1 lol

Heh, maybe I've been staring at it too long, but the first one's actually a pretty good approximation of what it looks like in person.

I thought it might be a bivalve, but I've never seen one that shape. Guess I'll just have to keep searching. Thanks for the input!

On an unrelated not, I have a crab named Bigfoot - my sister's the only one who's seen it and the photographic evidence looks remarkably like that of his namesake.